using System;
using System.Diagnostics;
using System.Globalization;
using Microsoft.VisualStudio.TestTools.WebTesting;

namespace SampleWebTestRules
{
    //-------------------------------------------------------------------------
    // This class creates a custom validation rule named "Custom Validate Tag"
    // The custom validation rule is used to check that an HTML tag with a 
    // particular name is found one or more times in the HTML response.
    // The user of the rule can specify the HTML tag to look for, and the 
    // number of times that it must appear in the response.
    //-------------------------------------------------------------------------
    public class CustomValidateTag : ValidationRule
    {
        /// Specify a name for use in the user interface.
        /// The user sees this name in the Add Validation dialog box.
        //---------------------------------------------------------------------
        public override string RuleName
        {
            get { return "Custom Validate Tag"; }
        }

        /// Specify a description for use in the user interface.
        /// The user sees this description in the Add Validation dialog box.
        //---------------------------------------------------------------------
        public override string RuleDescription
        {
            get { return "Validates that the specified tag exists on the page."; }
        }

        // The name of the required tag
        private string RequiredTagNameValue;
        public string RequiredTagName
        {
            get { return RequiredTagNameValue; }
            set { RequiredTagNameValue = value; }
        }

        // The minimum number of times the tag must appear in the response
        private int MinOccurrencesValue;
        public int MinOccurrences
        {
            get { return MinOccurrencesValue; }
            set { MinOccurrencesValue = value; }
        }

        // Validate is called with the test case Context and the request context.
        // These allow the rule to examine both the request and the response.
        //---------------------------------------------------------------------
        public override void Validate(object sender, ValidationEventArgs e)
        {
            bool validated = false;
            int numTagsFound = 0;

            foreach (HtmlTag tag in e.Response.HtmlDocument.GetFilteredHtmlTags(RequiredTagName))
            {
                Debug.Assert(string.Equals(tag.Name, RequiredTagName, StringComparison.InvariantCultureIgnoreCase));

                if (++numTagsFound >= MinOccurrences)
                {
                    validated = true;
                    break;
                }
            }

            e.IsValid = validated;

            // If the validation fails, set the error text that the user sees
            if (!validated)
            {
                if (numTagsFound > 0)
                {
                    e.Message = String.Format("Only found {0} occurences of the tag", numTagsFound);
                }
                else
                {
                    e.Message = String.Format("Did not find any occurences of tag '{0}'", RequiredTagName);
                }
            }
        }
    }
}
